The Rockville Centre school district, which overpaid 44 teachers a total of $250,000 ending last fall, has since changed some of its policies regarding raises -- and has replaced its internal and external auditors for failing to pick up the error.

Superintendent William Johnson said the district already has recouped much of the money: Some of the educators involved elected to pay it back in a lump sum, while others have chosen to repay it over a three-year period.

"We will get it all back," Johnson said of the funds.

Investigators with the law firm Ingerman Smith, hired by the district to look into the matter, found the mistake arose from "an incorrect interpretation" of a provision of the teachers' contract. As a result, dozens of teachers received double the percentage increase they were supposed to get.

The issue has since been addressed, Johnson said.

"Everything has to be countersigned by at least two people," he said. "Even when interpretations are made of the contracts, it cannot be put in place unless a minimum of two people sign off on it. "

Investigators, who used a forensic accountant to assist in the query, did not find malfeasance.

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"No employee involved in the decision that resulted in the overpayment personally benefited from the salary change, and there was no scheme with the affected teachers' bargaining unit members to provide the additional monies," they said.

Internal and external auditors, who examined the district's records for each of the three years during which the overpayments occurred, did not discover the problem.

Instead, the error was uncovered by the district's own business office while it was applying contract increases for the 2014-15 school year.